Railway track construction



March 3, 1959 c. WEBER ET AL RAILWAY TRACK CONSTRUCTION Filed Sept. 21,1954 FIG.

RNVENTORS.

WEBER TH L. HENSON ATTORNEYS CARL BY KENNE Y thereto the correct gaugespacing apart.

Y crosstie construction 1s United States Patent O 2,875,953 RAILWAYTRACK CONSTRUCTION Carl Weber, New York, N. Y., and Kenneth L. Henson,Rochelle Park, N. J., assignors, by mesne assignments, to Carl Weber,New York, N. Y.

Application September 21, 1954, Serial No. 457,406 4 Claims. (Cl. 238-2)This invention relates to the construction of railway tracks. Theinvention is characterized by the provision of rail-supporting crosstieslabs, of precast concrete or equivalent imperishable material, whichprovide more effective support for the rails than is afforded by con-vcrossties for the support of the steel rails which are spiked To reducethe rail pressure on the ties, steel plates are inserted under therails. These steel plates also serve lateral shearing stresses to thespikes.

The crossties rest on a crushed stone or gravel 'ballastA b ed.` Thetrack is stabilized in vertical position by compacting the ballast underthe ties. These must be placed some distance apart from each other topermit the use of ballast tampers on both sides of every crosstie. Thusthe supporting value of every crosstie is limited to its com pactedsurface area, and the rail between ties is subjected to bendingstresses. Since the bearing value of the crosstie foundation cannot beincreased, it has become necessary to adopt very heavy steel rails tomeet the ever increasing demands for heavier and speedier train service.

One of the largest items of cost inrailway operations is for themaintenance of the track. The perishable wooden crossties mustfrequently be replaced. Water from rain or melting snow penetrates theballast bed, causing softening of the supporting soil with consequentsubsidence of the track. These deficiencies must periodicallybe`corrected to maintain safe traic conditions.

Our new railway track construction eliminates Ythev use of woodencrossties with their tie plates and spikes, andA the disadvantagesincident thereto. It also renders the use of stone or gravel ballastsuperfluous. In accordance with our invention, the railway trackcomprises a plurality of rail-supporting crosstie slabs, andrailssnpported on and secured to said slabs, said slabs having a'lengthin the direction of the roadbed materially greater than the spacingbetween them, and thereby providing direct bearing support for the railsover substantially more than fifty percent of their length. Preferably,the slabs have a length in the direction of the track at leastthree'times greater than the spacing between them so that they provideVdirect bearing support for the rails over atleast seventy-five percentof the llength thereof. The roadbed material underlying the slabs isuniformly lcompacted so as to provide a substantially uniformdistribution of load bearing capacity over substantially the entire areaof each slab. The slabs thus provide maximum support for the rails, andenable rails of given weight to carry greater and faster-moving loadsthan when conventional wooden employed. The rail-supporting slabs usedintrack construction according to the invention are preferably ofreinforced of construction of rail-V to equalize the slabs are exemplaryonly,

ICC

(or prestressed) concrete, and are preferably precast by' massproduction methods. Metallic rail fastenings, such as bolts to whichrail clips and nuts can be applied, are preferably permanently anchoredin the slabs. At least one fill-injection opening preferably is formedin the central portion of each slab, for injecting roadbed fill materialunder the slabs to insure that the load bearing capacityof the roadbedis uniformly distributed over substantially the entire area of the slab.

These and other features of the invention are described below withreference to the accompanying drawing, in which Fig. 1 is a plan of arailway track constructed in accordance with the invention;

Fig. 2 is a section taken substantially along the line 2-2 of Fig. l;and v Fig. 3 is a section taken substantially along the line 3-3 of Fig.l.

The track shown in the drawings comprises roadbed 5 on whichrail-supporting slabs 6 are laid. Rails 7 are laid on and secured tothese slabs. The slabs 6 are preferably of precast concrete whichadvantageously a graded is prestressed or is reinforced with steelreinforcing rods 8..

The width of the slabs, in the direction of the width of the track, ispreferably about equal to the width of conventional wooden crossties thecase of a standard gauge track). The thickness of the slabs in avertical direction may also be about the same as conventional woodenties However, the length of the slabs, in the direction of the length ofthe track, is substantially greaterthan the corresponding dimension of awooden crosstie. In the case of the slabs shown in the drawings, theirlength is approximately equal to the length of two conventional woodencrossties plus the space between them (usually between three and fourfeet in the case of a standard gauge railway). Slabs of such dimensionsare nottoo large to be handled conveniently by railway construction andmaintenance crews, and yet are large enough to provide for achievingsubstantially the f-ull advantages of the invention. However, theforegoing dimensions for the crosstie and the invention is not limitedthereto.

Each of the slabs 6 carries rail fastenings by which the rails 7 aresecured in place. In the slabs shown, the rail fastenings comprise bolts9 embedded and anchored in the precast slabs, and rail clips 10 whichbear against the rail flanges and are secured in place by nuts 11.However, so far as the invention is concerned, there is nothing criticalabout the form of the rail fastenings provided.

Each of the slabs 6 is formed with one or more fill# injection openings12 extending vertically therethrough and located in more or less centralareas of the slabs (three such openings are shown in the slabs portrayedin the drawing, but their particular number and location can .be variedover Wide limits, depending on the size between the slabs, it ispreferably narrow (generally less than a foot), and does not exceed onethird thelength of the slabs themselves, so that the rails mounted onthe.` slabs are supported over at least seventy-five percent of theirlength. ,In any event, .thespace' should .beinarrow enough so that thebeam length of unsupported rail be- (for example about eight feet invr(say six to eight inches) as follows: After the roadbed tween the slabsis short andv easily able to.. withstand the bending stresses imposed onit during normal service.

After the rails have been laid on the slabs and fastened inV place, theslabs are raised to. the correct height by pressure injection of roadbedll material through the holes 12..y The fill is preferably injected at acontrolled pressure, so that the roadbed structure underlying the slabsis compacted and the. resultant voids caused by said compaction arefilled with the fill material. This injection s continued until asubstantially uniform distribution of. load bearing capacity oversubstantially the entire area of each slab is obtained. The raising ofthe slabs to theicorrect height and the provision for uniformdistribution ofV load-bearing capacity beneath substantially the entirearea of each slab cause the slabs to exert a substantially uniform forceagainst the bottom of the overlying rails. The lill materialadvantageously is cementtious. in character, so that when it has set itforms a consolidated mass and provides for stabilizing the bedV on whichthe slabs rest. lTo retain the till material in place, the longitudinalsides of the slab are advantageously sealed by tamping with earth, sand,cinders, or the like, and the spaces, if any, between the slabs areadvantageously similarly sealed, as indicated at 14.. No other ballastis needed, except perhaps in special cases, as where peculiar drainagerequirements exist.

Where existing wooden crosstie tracks are to be reconstructed inaccordance with the invention, the existing ballastmaterial may be leftin place and may be sealed, after the slabs have been laid thereon, bypressure injection` of cementitious till tration of water below theslabs.

The lill injection holes 12 advantageously are left open, so as topermit later adjustment of the trackif uneven roadbed subsidence orother occurrence ever makes it necessary.

The outstanding advantages of our method of railwayv track constructionmay be summarized as follows:

The direct support of the rails for much the greater part` of theirlength by concrete tie slabs, instead of support for less than halftheir length by spaced wooden crossties,.provides for increaseduniformity in the distribu,k

tion of deadv and live loads over the roadbed area. Therefore,4 maximumground surface pressures of the track structure are 40% of those ofconventional wooden crosstie tracks. The concrete tie slabs cover theground area under them like a waterproof blanket, whereby penetrationofi waterinto the roadbed is minimized and consequent reduction ofground stability by changing moisture content is greatly reduced or mayeven be made impossible. Theweight ofthe concrete slabs and `theiruniform contactwith the roadbed as a result of pressure injection oftill materials, are of great importance for oband maintaining superiortrack stability. Reducedcost of rails (which may be of reduced weightfor. given loads and speeds), elimination Iof ballast, tie; andV massproduction of the concrete tieV slabs, all contribute totrackconstruction costs` that platesand. spikes,

are favorable by comparison with other methods.

Termites` and harmless. to` concrete crosstie slabs. immune to thedeteriorating `effects soilconditions, fungus growths and uences.

Costsv of track maintenance,Y one of the most severe obstacles toprofitable railway operation, are reduced lto a mere fraction of presentexpenditures.

The correctly stabilized track structure with greatly reducedloadpressures on. the; supporting ground, protested against intermittentrvariations of moisture content,;produeeithe greater'possible safety fortrainopera- Wherever subsidence.; of .tracks ontills or adverse soilThese slabs. also are of acid or. alkaline other destructiveinmaterialto prevent the pene-A correspondingly reduced,-generally to abouty otherinsects destructive to Wood arek v conditionsV occurs, corrected at lowcost by pressure injection of additional f curing the rails to the slabsalong the resulting @rangement is .easily lill material.

The improved rail support provided by the invention leads to longerlifetime of the rails and equipment, and also decreases the cost ofoperation.

'The greatly increased contact area of the rails on the concrete surfaceof the supporting tie slabs, and the improved fastening of the rails,minimizes the dangers of rail creeping. y

It is quite evident that these advantages all lead to increased safetyand economy in railway construction and operation..

It is of course apparent that the design and construction of ourconcrete tie slabs are subject to variation to meet specific needs. Ribsor stifeners may be provided where soil conditions or traiiclrequirements must be considered. Special slabs may be furnished forswitches, and for rail andv road crossings. Resilient pads of variouskindsv may be inserted under the rails to subdue train noises, and otheraccessories can be incorporated in the track structure to meet the mostexacting requirements of every type of railway track construction andservice;

In the appended claims the term roadbed is used to designate the groundupon which the railway is to be laid Without rapplication thereto of theusual rock ballast.

We claim: v

l. The method of laying a railway track which comprises leveling theroadbed to line and grade, laying railway supporting cross-tie slabsdirectly on the established grade so that-the distance between therespective slabs is less than about one half the width of a slab, se-

substantially normal to the lengthwise direction of the space lbetweenthe slabs, and pressure-injecting roadbed till material beneath theslabs to compact the roadbed beneath them and to till the voids causedby said' cornpaction with the fill material, said pressure-injectionbeingY continued until the slabs are raised and exert a substantiallyuniform force against the bottom of Vthe overlying railsV and asubstantially uniform distribution of load-,bearing capacity beneath therails under substantially the entire area of each slab has beenobtained.

2. The method-of laying a railway track as set forth in claim 1 inwhichA the roadbed lill material is cementitious invcharacter and isinjected ata controlled pressure through openings extending through saidslabs from ther top to the bottom. v

3. The method of laying a railway track as set forth in claim 2 inwhich-the roadbed fill materialis confined substantially to the areaunderlying the slabs until it has set to forma-consolidated, stabilizedroadbed mass.

4. lThe method of laying a railway trackas set fort-h inclaim 1 in whichthe distance between the respective slabs does not exceed more than onethird the width of aV slab. Y 4

References Cited in the file of thisv patent UNITED STATES PATENTSGermany v Sept..29,

parallel lines extending,-

